Hi there. While new to MInt, I've been a user of Ubuntu since Heron so I wouldn't have said I'm a complete beginner, but I'm stuck with this one...

Attempting to open a video file of any file type causes the default player to open, go to fullscreen, not get so far as playing a single frame, then crash out the desktop environment back to the login screen. I can't play a video file by selecting it, and I have only been able to get VLC to play anything at all from the command line, and only that after opening VLC from the Applications menu and setting its output to X11 rather than default. Opening Totem or VLC without media doesn't cause a crash.